Diabetic kidney disease (DKD) is one of the major vascular complications of diabetes, which is associated with glomerulosclerosis and poor perfusion. Therefore, improving the renal perfusion may help to halt or reverse the kidney injury. Here, we investigated whether transplanting mouse EPC (that has been modified by transiently silencing p53 gene using Adenovirus transduction ex-vivo), under renal capsule could improve angiogenesis and renal perfusion, by preventing EPC apoptosis in a hyperglycemic milieu.
Methods: First, we confirmed hyperglycemia and progressive proteinuria in STZ-induced type 1 diabetic C57BL/6J mouse. Next, we transplanted 0.3 million p53-silenced EPCs,or Ad-Null-EPCs (control), bilaterally, under each kidney capsule. Another comparator was non-STZ normal mouse. Urine was collected weekly for volume and protein estimation. Renal blood flow was measured by laser Doppler. Kidneys were harvested post sacrifice and qRT-PCR were performed for targeted (towards angiogenic genes) gene expression assays.
Results: Excess urine volume as noted in the hyperglycemic mouse models was reduced 4-fold post transplantation of p53sh-EPCs compared to null. There was no proteinuria after week 2 in p53sh-EPC transplanted mouse unlike control. Enhanced blood flow by laser doppler (3.2 fold) was also noted with delivery of p53sh-EPCs compared to null EPC. Absence of proteinuria (after 2 weeks) and renal blood flow measurements for p53sh group were similar to the non-STZ mouse. Interestingly, markers for neovascularization, such as eNOS (4.5 fold, p=0.002) and VEGF-A (1.5 fold, p=0.03) upregulated significantly post p53 silenced EPC transplantation compared to null EPC. CD31 staining is pending.
Conclusion: Transient silencing of p53 gene in mouse EPCs help to improve proteinuria, diabetic polyuria and renal blood flow, most likely by increasing angiogenesis and perfusion and may have a prominent therapeutic role in DKD.
N. Kundu: None. L.D. Asico: None. C.C. Domingues: None. N. Ahmadi: None. S. Sen: None.